/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/TriangleMesh.h
The GetFaceNormals functions assume Counter Clockwise triangle windings in a Left Handed coordinate system If this is not the case the returned face normals may be inverted
[TArray](API\Runtime\Core\Containers\TArray)< [FVec3](API\Runtime\ChaosCore\Chaos\FVec3) > GetFaceNormals ( const [FParticles](API\Runtime\Chaos\Chaos\FParticles) & InParticles, const bool ReturnEmptyOnError ) const